\(\hept{\begin{cases}x-y=3\\3x-4y=2\end{cases}}\)
\(\hept{\begin{cases}x=y+3\\3x-4y=2\end{cases}}\)
\(\hept{\begin{cases}x=y+3\\3y+9-4y=2\end{cases}}\)
\(\hept{\begin{cases}x=y+3\\y=7\end{cases}}\)
\(\hept{\begin{cases}x=10\left(tm\right)\\y=7\left(tm\right)\end{cases}}\)
Vậy (x;y)=(10;7)
\(\hept{\begin{cases}\frac{x}{2}-\frac{y}{3}=1\\5x-8y=3\end{cases}}\)
\(\hept{\begin{cases}x-\frac{2y}{3}=2\\5x-8y=3\end{cases}}\)
\(\hept{\begin{cases}x=\frac{2y}{3}+2\\10+\frac{10y}{3}-8y=3\end{cases}}\)(thay x =2y/3 + 2 vào bthuc bên cạnh )
\(\hept{\begin{cases}x=2+\frac{2}{3}y\\-\frac{14}{3}y=-7\end{cases}}\)
\(\hept{\begin{cases}x=2+\frac{2}{3}\cdot\frac{3}{2}=3\\y=\frac{3}{2}\end{cases}}\)
Vậy (x;y)=(3:3/2)
